Glass material is smudgy and doesn't look like glass
Some things that could help:

To brighten shadows inside the glass, add more Transmission bounces
For shooting glass (and other shiny objects), use high-contrast lighting
Denoiser still needs a lot of samples to avoid artifacts and smudges


3-4 lights, HDRI environment, 1000 Render Samples + Denoiser


Related:
How to make this glass more realistic?
How to illuminate the darkness inside glass objects in Cycles?